A three-year legal fight following the 2008 deaths of a Denver family from carbon monoxide poisoning in an Aspen-area mansion has ended after the three plaintiffs reached a settlement with the final defendant and his construction company.

The settlement — the terms of which were not disclosed — was announced Thursday by William Hansen, the Denver attorney for relatives of Parker Lofgren, 39, and Caroline Lofgren, 42, and their children, Owen, 10, and Sophie, 8.

The family, which had won a stay at 10 Popcorn Lane 4 miles east of Aspen in a school auction, died after a boiler used to heat the home’s hot water and snowmelt systems spewed the odorless poisonous gas into the rest of the residence.

In 2010, a Pitkin County grand jury brought criminal charges against two former government building inspectors who allegedly signed off on the home and against a plumbing and heating contractor who allegedly improperly installed the boiler. The charges were later dismissed after a judge ruled they were brought outside the three-year statute of limitations for such charges.

Also that year, the Lofgren relatives sued in Denver federal court a host of individuals and companies that worked on the home, which at one point was for sale for nearly $9 million.

Jean Rittenour of Portland, Ore., Parker Lofgren’s mother; Frederick Feuerbach of Lenox, Mass., Caroline Lofgren’s father; and Hildy Feuerbach of Rockport, Mass., the sister of Caroline Lofgren, filed the lawsuit, which was later moved to Denver District Court.

“For me this was a very positive experience,” Hildy Feuerbach said Thursday of the lawsuit. “It was something that we had to do.

“I don’t regret it at all.”

Feuerbach said she has worked on the lawsuit almost full time for three years, motivated by what she said was her devotion for her deceased family members.

“This came from my love for them,” she said. “It was a way to honor them and find out what happened, in the hope that we can prevent such a tragedy in the future.”

Feuerbach and other family members have since helped pass legislation requiring carbon monoxide detectors in every residence in Colorado, Oregon, Maine and Washington.

Jonathan Thomas and his company, Black Diamond Land Development, were among the defendants in the suit, which included claims for wrongful death, manslaughter and negligence. They owned the house at the time of the incident.

Thomas and other subcontractors settled the case earlier this year.

The general contractor on the building of the home, Integrity Construction Management Group, and its owner, Jack Wheeler, were the last defendants to settle. That happened in late April, Hansen said Thursday.

In the press release, Hansen blasted the construction of the home, which did not have a carbon monoxide detector.

“Shoddy workmanship was pervasive, there were numerous building code violations, and there was lax oversight in the construction, compounded by miscommunication and a lack of adequate maintenance and repair while the house was” for sale, Hansen wrote.

Among the defects were poorly connected pipes on the boiler that “would inevitably fail,” the press release says. “Even after the house was occupied following construction, the regularly malfunctioning boiler was not adequately serviced or maintained such that the obvious defects were never discovered and repaired.”

When the pipes did fail, the gas built up in the home’s crawl space and spread to the bedrooms where the family was sleeping, Hansen wrote.

A sophisticated fire and burglar alarm system had been installed in the home, but less than $600 was saved when hardwired CO detectors in the alarm proposal were rejected, he wrote.

Representatives of the defendants either declined comment or could not be reached Thursday.

The case was one of the more complicated ones Hansen has handled in his nearly 30 years as an attorney, he said in an interview.

With “the number of defendants, the factual contentions and the engineering issues, it was a tough case,” he said.

Hansen said that his clients were also up against Colorado’s “antiquated” wrongful death laws that do not recognize the rights of grandparents. The plaintiffs were only able to pursue claims and damages for the deaths of Parker and Caroline Lofgren, not their children, Hansen said.

The plaintiffs hope the case spurs changes in those laws, according to the press release. The terms and amounts of the settlement are confidential, though the sides believe it was fair and reasonable, Hansen wrote.

Hildy Feuerbach said she needs “to take a little break now.” There are many in her family who have various ideas for initiatives on carbon monoxide awareness, she said. They will work together on some, but also go in different directions on others, she predicted.

Feuerbach said she hopes to put together a public service commercial. Areas lacking monoxide monitors include schools, dorms and hotels, she said.

“Certain changes should be made, and I would like to be an advocate for that,” she said. “It sounds like this will be full time again for me.